As a natural disaster, once a large earthquake occurs, it is often accompanied by the separation of loved ones. What makes people feel even more helpless is that it is almost impossible to complete earthquake prediction from a predictive level with current technology. However, the failure of prediction does not mean that early warning is impossible. This earthquake in Changning County successfully achieved early warning, which is inseparable from the joint role of sensors and the Internet.

Warning non prediction and earthquake wave race

The fundamental difference between earthquake warning and earthquake prediction is that the purpose of prediction is to make a warning about the possible range of earthquakes in the surrounding area before an earthquake event occurs, while warning is to issue a warning to the areas that may be affected before serious disasters occur after an earthquake has already occurred. In theory, earthquake warning can only reduce damage and cannot avoid casualties. Therefore, the faster the warning, the greater the reduction in casualties, and speed is the key.

So how can we improve speed? The basis of earthquake warning is the observation of seismic waves. Generally speaking, seismic waves consist of two parts: transverse waves and longitudinal waves, with different propagation speeds. Longitudinal waves propagate faster and cause less damage, making them important indicators for determining the location and magnitude of earthquake sources in earthquake monitoring. In fact, the propagation speed of destructive seismic waves is about 3.5 kilometers per second. Although it may seem very fast, there is still some room for warning compared to the propagation speed of radio waves, which is close to the speed of light. Specifically, by installing early warning sensors on roads and walls everywhere, they can collect data all the time like sentries. Once there is a shock wave, we can timely observe the ground shaking at different positions in a whole area. Then, through the Internet, we can transmit the data received by each sensor to the central calculator, so as to indirectly calculate the source position and the current propagation situation. Subsequently, as long as the data is transmitted to widely publicized media such as radio, television, and the internet through means such as the internet and radio waves, earthquake warning can be completed. In other words, all of this is actually the construction of a warning network. The more sensitive the sensors are and the more carefully they are laid, the faster the warning speed will be.

There are still shortcomings, but the flaws do not overshadow the virtues

The installation of earthquake warning networks has played a crucial role, but its shortcomings cannot be ignored. Specifically, there are two issues: one is the problem of accuracy. The law of early warning systems is that the closer they are to the epicenter, the faster the warning, and vice versa, the slower and less meaningful it is. In order to ensure the value of early warning, the entire process is not a detailed calculation and observation, but a rough consideration. The judgment of earthquake size, source and other information may not be accurate; The second is the enormous investment in manpower and material resources generated by the large-scale earthquake monitoring network and long-term data collection and calculation. Of course, the fact has proven its value, but earthquake prediction and seismic research are still several key areas that earthquake related scientific research projects need to break through.